SDCAR2010【逻辑入门】（六）Weaken

sdcar2010

By now, I hope you have already had a better understanding of the way to identify premises and conclusions and the roles played by each sentence in an argument. In essence, main point, role, and proceed by are Must-Be-True types of questions, which do NOT allow NEW evidence. In the following posts I will talk about a few question types which allow NEW evidence.

Weaken
Common Prompts for Weakening questions:

• Which one of thefollowing, if true, most seriously weakens the argument?
• Similar verbs: attack,call into question, cast doubt on, challenge, contradict, counter, damage,rebut, refute, undermine.
  

Before you look at the answers:

1. Pinpoint the main conclusionin thepassage. (Read my previous MainPoint post.)

2. Separate the premises from everything else. After you find the main point, don’t assume that all the other statements are premises; they might include opposing viewpoints, background information, and concessions.

3. Ask yourself, “Do the premises (exactlyas they are stated in the passage) support the conclusion (exactlyas it is stated in the passage)?” In other words, once discard everything else,how well do the premises support the conclusion? The reason you want to focuson exactly what the premises and the conclusion state is that you do not want to subconsciously make the argument better than it actually is. Do not help the author. Look at what he actually said and then decide whether his evidence stacks up:

? Does the authormake any unreasonable assumptions? For example, read the following statements: “We should support the proposed law, which requires government officials to disclose their annual incomes, because it will give ordinary citizens a fairchance to keep an eye on and more control over when and how elected officials receive gifts and benefits from lobbyists.” Watch out for should, moral ethical and other loaded conclusions. The test makers like to play off commonly held assumptions about what is right or wrong in our heads. This argument unreasonably assumes that “giving ordinary citizens a fair chance to keep an eye on and more control” is good. If this is the case, the author must clearly point out this premise in his argument.

• Does the authorrely on an unrepresentative survey/samples? For example, read the following statement: “Mr Xi will likely become the next President because over two-thirds of students in Fudan University said that they would vote for him.” Do these students represent fairly of the voters in the political process? Do these students even have the right to elect the next President?
  

• Does the authorrely on a questionable analogy or comparison? For example, read the following statement: “A terrorist caught by police in Xinjiang with explosives in his backpack should first be given a warning just like a vendor without license caught by urban management officers in Beijing. First offense is not a big deal.” My God. This cannot be happening!
  

? Does the author’s conclusion overstate the premises? For example, read the following statements: “Acupuncture has been shown to reduce the risk of stroke. Therefore, anyone who undergoes acupuncture treatment will not experience a stroke when they are older.” Do these words sound like a TV commercial? If you are good at CR, you can have a lot of funs to pick apart commercials in Chinese or English.


Then look for the answer that exploits one of those weaknesses:

• The correct answerusually offers new evidence that makes you doubt the conclusion without directly contradicting the original evidence in the passage.“Mr. Zhang will be a good addition to our finance department because he has worked in banks in Wall Street.” New evidence: “Mr. Zhang worked as a computer programmer in Wall Street.” This new evidence does not contradict the original premise, but it does cast doubt on the original conclusion. Another possible answer: “Mr. Zhang worked in Wall Street for a total of two weeks before beinglet go.” Still another: “Mr. Zhang recently had a big fight with our current finance VP during an M&A discussion.” Notice, this evidence is unrelated to the original premises; it has nothing to do with Wall Street. So do not skip ananswer choice because it does not address the points raised in the original argument. Focus on the new unfavorable light shining on the conclusion.
  

• Some arguments will tell you that two events are correlated (happened together) and thenconclude that one event causes the other. The problem with this kind of causal argument is that it relies on many questionable assumptions. If the conclusion states that A causes B (If reading my posts, a reader’s understanding of CR is increased), look for evidence that says
  

- B causes A (Areader with good understanding of CR tends to read my posts).

- C causes B or A or both (CDer whose English is superb are more likely to read my posts and have better understanding of CR).

-A and B are not actually correlated(The survey overestimated the increased understanding of CR for most readers after reading my posts).

Any evidence that supports one of these three possibilities will weaken the conclusion that A causes B. However, I do hope by reading my posts, you can improve your understanding of CR eventually.

SDCAR2010【逻辑入门】（五）Proceed by

SDCAR2010【逻辑入门】（七) Strengthen and Paradox

ST5

mark

我爱吃香菜

感谢分享！               

sa0314

Mark一下！               

梦季

感谢分享！               

梦季

Mark一下！               

lmumumumumu

感谢分享！               

陈生生

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hepuweizai

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Ayas

NN, thank you so much for your coach.

May I ask you a question. Just as you said, in a weaken question choice, if a new evidence is given and does not correlated with the original premise, it's also can be a true choice?